Patients treated in noisy operating theatres are more likely to suffer infections and need longer hospital stays, research has suggested.

A small study of 35 operations found patients were more likely to suffer surgical site infections (SSIs) when the environment was noisy.

Researchers analysed sound levels in decibels every second during a series of planned abdominal operations.

A questionnaire was also used to work out the behaviour of the surgical team during the operation, and the SSI rate within 30 days of the procedure was calculated.

Overall, six patients (17%) suffered an SSI. When the duration of the operation and other factors were taken into account, the study found a link between higher noise levels and SSIs.

Teams who talked about topics other than the surgery were linked with a significantly higher sound level in the operating theatre.

The authors concluded: "Intra-operative noise volume was associated with SSI. This may be due to a lack of concentration, or a stressful environment, and may therefore represent a ...parameter by which to assess the behaviour of a surgical team."

Dr Guido Beldi, staff surgeon and research group leader from Bern University Hospital in Switzerland, said: "SSIs lead to patients spending up to 13 days longer in hospital, making their stay cost up to three times as much.

"Having found a significant association between SSIs within 30 days of surgery and increased sound levels in the operating theatre, we can only conclude that noise is associated with a stressful environment or lack of concentration and this impacts on the surgical outcome."